FIELD: aluminum production processes and equipment. SUBSTANCE: method comprises alternation of stages of insufficient loading of alumina and stages of excess loading of alumina in comparison with mode of mean theoretically calculated flowrate of alumina in cell in dependence upon values calculated at termination of each control cycle (i) with duration T, mean resistance R(i) measured between terminals of cell, changing rate of that resistance or its gradient P(i), evolution rate of resistance gradient or curvature C(i) and extrapolated gradient PX(i)=P(i)+C(i) x T. Said values are compared respectively with standard (threshold) values Po,Co,Pxo. Alumina content in bath is sustained in rather narrow concentration range consisting (1.5-3.5)% according to respective algorithm for controlling it. EFFECT: enhanced accuracy of controlling alumina content. 22 cl, 3 dwg, 1 ex
